<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>margin属性讲解</title>
    <style type="text/css">
        span{
            background-color: lightgreen;
        }
        .xiongda{
            margin-right: 20px
        }
        .xionger{
            margin-left: 100px;
        }
        div{
            width: 200px;
            height: 200px;
        }
        /* 垂直方向上会出现外边距合并 外边距塌陷 */
        .box1{
            background-color: red;
            margin-bottom: 30px;
        }
        .box2{
            background-color: green;
            margin-top: 100px;
        }
    </style>
</head>
<body>
    <!-- 外边距: 一个盒子到另一个盒子的距离 -->
     <span class="xiongda">熊大</span>
     <span class="xionger">熊二</span>
     <div class="box1"></div>
     <div class="box2"></div>
</body>
</html>